26 March 2017 – The number of cholera cases reported by the Ministry of Health in Somalia has reached a cumulative 17 211 cases and 388 deaths with a case fatality rate of 2.25%, which is nearly 4 times as many as were recorded for the same period in 2016, and surpasses the total number of cases recorded in 2016.

While the AWD/ cholera epidemic has been controlled in Hiran, Banadir, Middle Shebelle and Galgadud, most of the recently reported cases were from inaccessible villages in Bay and Gedo regions.

The Ministry of Health and the health cluster led by WHO continue to collaborate with partners and health authorities on response and prevention activities around the country.

In order to address the inaccessibility of cholera treatment centres for people in inaccessible villages in Bay region, the Ministry has deployed doctors and health workers who were trained at Banadir hospital in Mogadishu on case management and surveillance. This is in addition to the 20 health workers already deployed in Bakool and Bay region.

Somalia is at the brink of another famine, after consecutive seasons of poor rainfall and lack of water have killed livestock and crops. This has left around 6.2 out of 12.3 million people in Somalia in need of humanitarian assistance. Nearly 3 million people face food insecurity and nearly 5.5 million people are at risk of contracting water-borne diseases. Hundreds of thousands of vulnerable people are also on the move in search of food, water, shelter and medical care.

Some of the key needs at present are safe food and water for the affected communities, essential medicines at treatment centres and funds to continue the training and deployment of health workers to the most hard-hit areas.

During March 2013–February 24, 2017, annual epidemics of avian influenza A(H7N9) in China resulted in 1,258 avian influenza A(H7N9) virus infections in humans being reported to the World Health Organization (WHO) by the National Health and Family Planning Commission of China and other regional sources (1). During the first four epidemics, 88% of patients developed pneumonia, 68% were admitted to an intensive care unit, and 41% died (2). Candidate vaccine viruses (CVVs) were developed, and vaccine was manufactured based on representative viruses detected after the emergence of A(H7N9) virus in humans in 2013. During the ongoing fifth epidemic (beginning October 1, 2016),* 460 human infections with A(H7N9) virus have been reported, including 453 in mainland China, six associated with travel to mainland China from Hong Kong (four cases), Macao (one) and Taiwan (one), and one in an asymptomatic poultry worker in Macao (1). Although the clinical characteristics and risk factors for human infections do not appear to have changed (2,3), the reported human infections during the fifth epidemic represent a significant increase compared with the first four epidemics, which resulted in 135 (first epidemic), 320 (second), 226 (third), and 119 (fourth epidemic) human infections (2). Most human infections continue to result in severe respiratory illness and have been associated with poultry exposure. Although some limited human-to-human spread continues to be identified, no sustained human-to-human A(H7N9) transmission has been observed (2,3).

CDC analysis of 74 hemagglutinin (HA) gene sequences from A(H7N9) virus samples collected from infected persons or live bird market environments during the fifth epidemic, which are available in the Global Initiative on Sharing All Influenza Data (GISAID) database (4,5), indicates that A(H7N9) viruses have diverged into two distinct genetic lineages. Available fifth epidemic viruses belong to two distinct lineages, the Pearl River Delta and Yangtze River Delta lineage, and ongoing analyses have found that 69 (93%) of the 74 HA gene sequences to date have been Yangtze River Delta lineage viruses. Preliminary antigenic analysis of recent Yangtze River Delta lineage viruses isolated from infections detected in Hong Kong indicate reduced cross-reactivity with existing CVVs, whereas viruses belonging to the Pearl River Delta lineage are still well inhibited by ferret antisera raised to CVVs. These preliminary data suggest that viruses from the Yangtze River Delta lineage are antigenically distinct from earlier A(H7N9) viruses and from existing CVVs. In addition, ongoing genetic analysis of neuraminidase genes from fifth epidemic viruses indicate that approximately 7%–9% of the viruses analyzed to date have known or suspected markers for reduced susceptibility to one or more neuraminidase inhibitor antiviral medications. The neuraminidase inhibitor class of antiviral drugs is currently recommended for the treatment of human infection with A(H7N9) virus. Antiviral resistance can arise spontaneously or emerge during the course of treatment. Many of the A(H7N9) virus samples collected from human infections in China might have been collected after antiviral treatment had begun.

Although all A(H7N9) viruses characterized from the previous four epidemics have been low pathogenic avian influenza viruses, analysis of human (three) and environmental (seven) samples from the fifth epidemic demonstrate that these viruses contain a four–amino acid insertion in a host protease cleavage site in the HA protein that is characteristic of highly pathogenic avian influenza (HPAI) viruses. Chinese authorities are investigating and monitoring closely for outbreaks of HPAI A(H7N9) among poultry.

Since April 2013, the Influenza Risk Assessment Tool has been used by CDC to assess the risk posed by certain novel influenza A viruses. Although the current risk to the public’s health from A(H7N9) viruses is low, among the 12 novel influenza A viruses evaluated with this tool, A(H7N9) viruses have the highest risk score and are characterized as posing moderate–high potential pandemic risk (6). Experts from the World Health Organization (WHO) Global Influenza Surveillance and Response System (GISRS) met in Geneva, Switzerland, February 27–March 1, 2017, to review available epidemiologic and virologic data related to influenza A(H7N9) viruses to evaluate the need to produce additional CVVs to maximize influenza pandemic preparedness. Two additional H7N9 CVVs were recommended for development: a new CVV derived from an A/Guangdong/17SF003/2016-like virus (HPAI), which is a highly pathogenic virus from the Yangtze River Delta lineage; and a new CVV derived from A/Hunan/2650/2016-like virus, which is a low pathogenic virus also from the Yangtze River Delta lineage (1). At this time, CDC is preparing a CVV derived from an A/Hunan/2650/2016-like virus using reverse genetics. Further preparedness measures will be informed by ongoing analysis of genetic, antigenic, and epidemiologic data and how these data impact the risk assessment. CDC will continue to work closely with the Chinese Center for Disease Control and Prevention to support the response to this epidemic. Guidance for U.S. clinicians who might be evaluating patients with possible H7N9 virus infection and travelers to China is available online (https://www.cdc.gov/flu/avianflu/h7n9-virus.htm).

Washington, D.C., March 28, 2017 (PAHO/WHO)—Brazil is carrying out mass vaccination campaigns for yellow fever in the states of Minas Gerais, Espirito Santo, Sao Paulo, Rio de Janeiro and Bahia, while strengthening surveillance and case management throughout the country since an outbreak of sylvatic yellow fever began in January. More than 18.8 million doses of vaccine have been distributed, in addition to routine immunization efforts.

The Pan American Health Organization/World Health Organization (PAHO/WHO) is providing specialized technical cooperation to the federal authorities managing the outbreak and has mobilized more than 15 experts, including experts from the Global Outbreak Alert and Response Network (GOARN), in disease control, surveillance, virology, immunization and other fields to collaborate with health officials in the affected states. These experts have been operating with field teams in surveillance, response, and control operations in Minas Gerais, Espirito Santo and Rio de Janeiro States.

Brazil’s Ministry of Health has reported 492 confirmed cases of yellow fever as of March 24, with 162 confirmed deaths. Another 1101 suspected cases are under investigation. A total of 1,324 epizootics, or deaths from yellow fever in primates, have been reported to the Ministry of Health, and 387 of these were confirmed by laboratory or epidemiological link, while 432 others are still being investigated.

So far, in the four states with confirmed yellow fever human cases– Minas Gerais, Espírito Santo, Rio de Janeiro and São Paulo– all cases have been linked to transmission through the jungle mosquito species Haemagogus and Sabethes. But confirmed cases in humans and monkeys in municipalities close to large urban areas indicate a potential risk of urbanization, and yellow fever activity has increased in ecosystems of tropical and sub-tropical forests that are close to human populations.

Officials are working to contain the virus so it does not spread to cities where it could infect Aedes aegypti urban mosquitoes. Until now there is no evidence of human cases of yellow fever virus infection transmitted by that mosquito.

Case numbers have been declining in Minas Gerais and Espirito Santo, but close monitoring of cases is continuing and Brazil is strengthening its capacity to quickly detect and treat cases of yellow fever. Vector-borne diseases have a seasonal characteristic in tropical areas and it is expected that new cases will diminish during dry and cold weather seasons.

Vaccination

Yellow fever can be prevented by means of an effective, and affordable live attenuated virus vaccine. PAHO/WHO recommends only one dose of the vaccine, which is sufficient to confer sustained immunity and life-long protection against yellow fever disease. The yellow fever vaccine is contraindicated in seriously immunosuppressed individuals. People over the age of 60 should only receive a vaccine after a careful risk-benefit assessment. The yellow fever vaccine should not be given to pregnant women, except those with high risk of infection and situations where there is an express recommendation from health authorities, or to infants aged less than 6 months, or to people with acute febrile illness.

PAHO/WHO currently recommends that countries prioritize, for vaccination, populations living in endemic areas and travelers to these areas, and that they expand vaccination to the routine vaccination of children at the national level if vaccines were available. It is important that countries share YF vaccination coverage estimates at the local level for children and adults in order to inform an accurate risk assessment of the current situation.

Mass immunization campaigns have started in the affected states. Federal public health authorities in Brazil have distributed 18.8 million doses of yellow fever vaccine since January to the states and municipalities in the areas where cases have been reported. These include the states of Minas Gerais, Espírito Santo, São Paulo, Bahia, and Rio de Janeiro. This effort is in addition to the country’s routine yellow fever vaccine programs in 19 states, which included 3.7 million doses of vaccine.

The extra vaccines include 3.5 million doses of yellow fever vaccine that Brazil requested from the emergency stockpile held by the International Coordinating Group (ICG) on Vaccine Provision, and have arrived in the country. The ICG includes four agencies: the World Health Organization (WHO), United Nations Children’s Fund (UNICEF), the International Federation of Red Cross and Red Crescent Societies (IFRC), and Médecins Sans Frontières (MSF).

The WHO Secretariat recommends vaccination against yellow fever at least 10 days prior to travel for travelers going to areas in Brazil where there is risk of yellow fever transmission, including the State of Rio de Janeiro, with the exception of the urban areas of Rio de Janeiro City and Niterói, and the State of São Paulo, with the exception of the urban areas of São Paulo City and Campinas. The WHO Secretariat recommends vaccination in the whole states of Espirito Santo and Minas Gerais. The information is being continuously updated.

Yellow fever in the Americas

Sylvatic Yellow Fever is endemic in areas of 13 countries and territories of the region, including Argentina, Brazil, Paraguay, Bolivia, Peru, Ecuador, Colombia, Venezuela, Panama, Guyana, Surinam, French Guiana and the island of Trinidad. In Brazil, 21 of the 27 states and the Federal District are considered to have areas at risk for Yellow Fever transmission. Globally, 47 countries have areas with endemic yellow fever: 34 in Africa, and 13 in Central and South America. Mass immunization is the most effective way to prevent disease.